1. Field of the Invention
The present invention concerns a double-side lamination system for thermocompression bonding of transparent films on both side surfaces of an ID card or the like.
2. Description of the Prior Art
Recently, ID cards of various types are being widely used. In order to protect an ID card from tampering or to improve the life of the ID card, a transparent film of about 30 μm in thickness is laminated by a thermocompression bonding on a surface of the ID card on which information data are printed. Lamination systems such as disclosed in U.S. Pat. No. 5,807,461, U.S. Pat. No. 5,783,024 and U.S. Pat. No. 6,159,327 are known as systems suitable for such lamination.
In the lamination system disclosed in U.S. Pat. No. 5,807,461, a transparent film pre-cut in a predetermined shape (a patch) is mounted on a carrier (a base sheet). The carrier is provided with sensor marks (index markings) for detecting the position of the pre-cut patch on the carrier. The lamination system detects the sensor mark prior to the lamination to detect the position of the pre-cut patch, then tears the patch from the carrier and laminates the patch on the surface of the printed ID card by thermocompression bonding. Such lamination system is undesirable in view of the operational cost and the protection of the environment, since the carrier is thrown away as a waste material.
In a lamination system such as disclosed in U.S. Pat. No. 5,783,024 or in U.S. Pat. No. 6,159,327, a leading edge of a continuous transparent laminate film is drawn out from a supply roll, then transferred along a film transfer path, and then cut into a predetermined length. The cut laminate film is further transferred along the film transfer path to a convergence zone. On the other hand, a card is put into the lamination system after being printed by a card printer. The card is also transferred along a card transfer path to the convergence zone. The cut laminate film is laid on the card at the convergence zone. The cut laminate film and the card are then transferred to a thermocompression bonding part, where they are bonded with each other by thermocompression bonding using a heat roller or heat rollers provided there.
Such lamination system, also called wasteless type lamination system, is advantageous since the laminate film is used after being cut in a necessary length, and accordingly, no waste carrier such as in the lamination system disclosed in U.S. Pat. No. 5,807,461 is left.
The lamination system disclosed in U.S. Pat. No. 6,159,327 is a double-side lamination system that is to be used solely for double-side lamination. However, some cards are required to be laminated on both surfaces, others are required to be laminated on only one surface of each of the cards, depending on the types of the cards such as driver's licence cards, ID cards or social insurance cards, for example. Since the lamination system disclosed in U.S. Pat. No. 6,159,327 can be used for only double-side lamination, and can not be used for lamination in accordance with various types of the cards, there is a problem that a user of the lamination system is obliged to prepare a plurality of different lamination systems and to select and use one of them in accordance with the type of the cards to be issued.